Skin-like covering, especially for vehicle interior parts like arm rests, central consoles, door surfaces, instrument panels or the like of motor vehicles, and method of making a skin-like covering

ABSTRACT

A skin-like covering, especially for automotive vehicle interior parts, like armrests, central consoles, door covers, instrument panels or the like of automobiles, has at least one pigment containing layer ( 11, 12 ) applied to a shape imparting surface of a liquid polymer reaction mixture. At least two layers ( 11, 12 ) are provided, namely a lacquer layer ( 11 ) of at least one layer forming the outer surface and containing the color pigment, and a support or carrier layer behind the lacquer layer and formed of at least one layer. The lacquer layer ( 11 ) and the support or carrier layer ( 12 ) are each composed of a reactive polymer aqueous single-component or multicomponent dispersion and a respective cross linker.

SPECIFICATION

This application corresponds to German applications 10 2004 008 205.7filed 18 Feb. 2004 and 10 2004 055096.4 filed 15 Nov. 2004 under 35 USC119 and the International Convention.

FIELD OF THE INVENTION

The invention relates to a skin-like covering for vehicle interiors, armrests, central consoles, door covering, instrument panels and the like.

The invention also relates to a method of making such a covering.

BACKGROUND OF THE INVENTION

It is known to provide especially the interior spaces of motor vehicles,like, for example, arm rests, central consoles, door linings, instrumentpanels and other covered parts which may be found in the interiors ofautomobiles, with a skin-like covering. Such a skin-like covering shouldsatisfy the aesthetic and tactile requirements of the vehicle user. Thusthe surface of such a skin-like covering with an appropriate color orwith a special structure, for example with a leather structure, shouldbe capable of positively influencing the value of the vehicle from avisual point of view for the vehicle user.

From the tactile point of view, the skin-like covering should providethe vehicle user with a pleasant touch and grip, that is providedesirable properties upon contact of the person of the user with thecovering and the pressure of the covering against the person.

A skin-like covering known from DE 38 75 029 T2 in accordance with theprinciples described at the outset, can comprise a monostructured PURpolyurethane layer which is applied as a liquid reaction mixture in theform of a sprayed skin of a gel with droplets of different sizes. Theknown skin-like coverings, however, were susceptible of improvement inthat they were of limited versatility and involved a high cost ofmaterials.

OBJECTS OF THE INVENTION

It is the object of the invention, using as a starting point theabove-described covering, to so improve the known covering that withrespect to its structure, it will offer greater versatility in form andcan be produced more economically.

Another object of the invention is to provide a method of making theimproved covering.

SUMMARY OF THE INVENTION

These objects are achieved in accordance with the invention with atleast two layers, namely by one outer-surface-forming and at leastsingle-layer laquer coating comprising color pigments and by an at leastsingle-layer support coating lying behind the laquer coating, wherebythe laquer coating or layer and the support coating or layer each areformed from a reactive polymeric single-component or multicomponentaqueous dispersion with a respective cross-linker or cross-linkingagent.

The skin-like covering according to the invention has the followingsignificant elements:

The skin-like covering is comprised of at least two layers, namely froman outer-surface-forming at least single-layer laquer coating or layerand from an at least single-layer support coating or layer carrying thelaquer layer or coating.

The subdivision of the covering skin according to the invention into anouter laquer layer and a support layer lying therebeneath from theoutset affords a substantially greater range of variations inapplications. Thus, for example, with the use of a unitary support orcarrier layer relative to the laquer layer alternatively usable andoptionally selectable color tones can be employed. Additional variationpossibilities arise for different purposes or uses by the provision ofcarrier or support layers of different compositions.

In contradistinction to the previously known spray skin according to DE38 75 029 T2 which has a single composition over the entire thickness ofthe layer forming the skin, with the invention the more expensivecomponents like the color pigments can be limited to the relatively thinlaquer layer while the carrier or support layer deals with the strengthand thus allows the cost of materials to be reduced.

The laquer layer can be comprised of a single-component ormulticomponent material composition.

Thus the laquer layer can be formed from a reactive aqueous polymerdispersion. By the choice of different components of the composition,the laquer layer can, for example, be given a smooth feel, a dry feel orboth or some other response to touch.

In a further feature of the invention, the laquer layer is comprised ofan acrylate or a polyacrylate and a cross-linking agent. As thecross-linking agent, for example, an isocyanate or carbodiimide orpreferably a polycarbodiimide can be used.

The laquer layer has a compact structure. The laquer layer can beapplied by entrainment in a pressurized gas and/or in compressed air,that is, sprayed onto a surface. With this finest gas-supported orcompressed-air-supported atomization, the droplet size of the reactiveaqueous polymeric dispersion can be about 5μ to 100μ, preferably about30μ to about 60μ.

The laquer layer can be a single layer or can be composed of a pluralityof layers.

The thickness of the laquer layer can amount to between 10μ and 300μ,preferably between 60μ to 90μ.

The very fine gas-supported or air-supported atomization of the reactiveaqueous polymeric dispersion for the laquer layer results in ahomogeneous and bubble-free surface which, conditioned upon the sprayingonto an engraved form (engraved surface of a tool) will reproduce theengraving, that is its texture or graining, free from defects.

In addition the invention can apply the laquer layer in a plurality ofcolors adjacent one another, whereby effect lacquering is possible.

The colors or color tones of each laquer layer can be adjusted by theaddition of corresponding coloring pigments.

Further, the invention provides that the laquer layer can containmaterial components which are known in the art and which have alight-stabilizing effect.

In a further feature of the invention, the carrier or support layer iscomprised of a polymeric elastomer layer which is also produced from anaqueous dispersion. This dispersion is comprised, according to theinvention, of a reactive aqueous PUR dispersion. The carrier or supportlayer contains as the cross-linking agent also an isocyanate orcarbodiimide or, preferably, a polycarbodiimide. As has already beenindicated, the carrier or support layer bestows the strength to thecovering skin.

The carrier or support layer also can, corresponding to the invention,be formed as a single layer or as a plurality of layers from asingle-component or a multicomponent material composition. The thicknessof the carrier or support layer can amount preferably to about 0.3 mm toabout 1.0 mm.

The carrier layer or support layer, according to the invention, is alsosprayed with the aid of pressurized gas or compressed air. By means ofthe very fine gas-supported or air-supported atomization, a droplet sizeof about 5μ or 100μ, preferably from about 30μ to 60μ is produced.

The carrier layer or support layer of the covering skin can have a PURfoam-backed carrier which itself can be backed by a suitable moldable orpressable mass so that the laquer layer, carrier or support layer andPUR form can form the covering with its high quality surface.

The invention is comprised, in addition, of a method of making askin-like covering, especially for automotive vehicle interior parts,like arm rests, central consoles, door coverings; instrument panels orthe like of automobiles, in which at least one color-pigment-containingliquid polymer reaction mixture is applied to a shape-imparting surfaceof a tool. A process of this type is known from DE 38 75 029 T2.

The method according to the invention differs from that process in thatinitially a laquer layer formed from a cross-linker containing reactivepolymeric aqueous single-component or multicomponent dispersion issprayed in one or more layers onto an engraved surface of optional shapeand surface contour, like for example, a leather graining, and then asupport layer is applied to the back side of the lacquer layer in one ormore layers of a cross linker containing reactive polymeric aqueoussingle-component or multicomponent dispersions, whereby both the lacquerlayer and the support layer are deposited by means of pressurized gasand/or by means of compressed air.

Both the application of the lacquer layer and the application of thesupport or carrier layer take place with a variably adjustable meteringof the material, with a variably adjustable atomization of the material,with a variably adjustable spray jet configuration and with a variablyadjustable spray jet deflection.

The material temperature both for the lacquer layer dispersion and alsothe support layer dispersion amounts preferably to 20° C. to about 120°C.

Both the lacquer layer and the support or carrier layers can beone-component or multicomponent compositions.

The lacquer layer and the support or carrier layer are sprayed one afterthe other onto a shape-forming engraved surface. The engraved surfacecan for example be a temperature-controlled shell, preferably of metal,like, for example, of aluminum, steel or nickel. It has also been foundto be advantageous to heat the shell, that is the engraved surface, toan operating temperature of about 120° C.

The method of the invention can be used to form simple contours, forexample planar contours and contours with simple geometry as well ascomplex, undercut contours.

From the point of view of the device for practicing the method accordingto the invention, the nozzle spray head can be moved with respect to theshape-forming engraving or, conversely, the shape-forming engraving canbe moved with respect to the nozzle spray head.

For producing undercut surfaces, it has been found to be advantageous tobe able to move the nozzle spray head with all possible degrees offreedom of movement in space relative to the layer receiving surface.

The nozzle spray head is advantageously configured as a two-material ortwo-component spray head for atomizing the aqueous dispersion withpressurization gas or compressed air.

BRIEF DESCRIPTION OF THE DRAWING

In the drawing, both the covering skin as well as the device with itsassociated method are schematically illustrated by way of example. Inthe drawing:

FIG. 1 is a perspective view illustrating a part of a covering;

FIG. 2 is a partial section corresponding to the detail encircled at IIin FIG. 1; and

FIG. 3 is a sectional view of a device for producing a covering skin.

SPECIFIC DESCRIPTION

In FIG. 1 a partial region of a covered part, like for example aninstrument panel, is indicated with the reference numeral 10. The crosssection according to FIG. 2 shows a skin layer, namely the lacquercoating 11, a support coating 12, a PUR [polyurethane] foam layer 13 aswell as a carrier 14.

The lacquer layer 11 is composed of a reactive aqueous polymericdispersion which contains acrylate or polyacrylate and as a crosslinking agent or cross-linker a carbodiimide or polycarbodiimide. Thethickness of the lacquer layer 11 amounts to about 100μ.

The support layer 12 is composed of a reactive aqueous PUR dispersionwhich also contains carbodiimide or preferably polycarbodiimide as thecross-linker.

The lacquer layer 11, especially, contains the requisite color pigments.

The support layer has a thickness between 0.3 and 1 mm.

The support or carrier layer 12 is backed by the PUR foam layer 13 whichis a multiple of the thickness of the support or carrier layer 12. Allof the layers 11, 12, 13 cover the shape-determining support part 14 ofthe covered member 10. The support part 14 can for example be aninjection molded part of plastic, a blow molded part or a part made bypressing.

In FIG. 3 a device and method for producing a covering skin has beenschematically illustrated.

A mold 15, for example of a chromium-nickel steel or of aluminum, withan undercut mold cavity 16 has in cross section generally polygonal likeengravings (engraved surface) 17 extending thereon. The engraving 17 canhave a surface structuring, for example a leather-like graining. Themold 15 is advantageously heatable in a manner not shown, for example,by means of electric heating cartridges or by means of passages throughwhich a heating liquid can be passed. In this manner an operatingtemperature of for example 80 EC can be provided. An appropriate nozzlespray head 18 extends into the mold cavity 16 and has been shownschematically and can produce a spray supported by pressurized gasand/or compressed air of the respective active aqueous polymerdispersions for the layers 11 and 12.

The nozzle spray head 18 should be movable in space with all possibledegrees of freedom corresponding to the arrows a, b and c. In thismanner, even with undercuts it is possible to initially deposit thelacquer layer 11 and then the support layer 12 of the covering skinrepresented as a whole at H in the mold 15 by atomizing the respectivedispersion.

1. A skin-like covering for automotive vehicle interior parts includingarm rests, central consoles, door covers and instrument panelscomprising an at least single-layer lacquer coating containing colorpigment and forming an outer surface, and an at lest single-layersupport or carrier coating lying behind the lacquer-layer and whereinthe lacquer layer and the support or carrier layer are each formed of areactive polymer aqueous single component or multicomponent dispersionand each contain a cross linker.
 2. The skin-like covering according toclaim 1 wherein a polymer component of the lacquer layer is comprised ofacrylate or polyacrylate.
 3. The skin-like covering according to claim 1wherein the polymer component of the lacquer layer is comprisedexclusively of acrylate or polyacrylate.
 4. The skin-like coveringaccording to claim 2 wherein a polymer component of the support orcarrier layer is comprised of polyurethane.
 5. The skin-like coveringaccording to claim 4 wherein the polymer component of the support orcarrier layer is comprised exclusively of polyurethane.
 6. The skin-likecovering according to claim 4 wherein the cross linker of the lacquerlayer is comprised of an isocyanate or of carbodiimide.
 7. The skin-likecovering according to claim 6 wherein the cross linker of the lacquerlayer (11) is comprised of polycarbodiimide.
 8. The skin-like coveringaccording to claim 6 wherein the cross linker of the support or carrierlayer is composed of an isocyanate or a carbodiimide.
 9. The skin-likecovering according to claim 8 wherein the cross linker of the support orcarrier layer is composed of polycarbodiimide.
 10. The skin-likecovering according to claim 9 wherein the thickness of the lacquer layer(11) is between 10μ and 300 μ.
 11. The skin-like covering according toclaim 10 wherein the thickness of the lacquer layer amounts to betweenabout 60μ and 90 μ.
 12. The skin-like covering according to claim 10wherein the lacquer layer (11) has a compact structure.
 13. Theskin-like covering according to claim 10 wherein the support or carrierlayer has a microcellular structure.
 14. The skin-like coveringaccording to claim 12 wherein lacquer layer is formed by spraying thereactive polymer aqueous dispersion to which a pressurized gas and/orcompressed air is supplied.
 15. The skin-like covering according toclaim 14 wherein the droplet size of the gas-supported and/or compressedair supported reactive polymer aqueous dispersion of the lacquer coating(11) amounts to about 5μ to about 100 μ.
 16. The skin-like coveringaccording to claim 10 which has a plurality of lacquer layers appliedone adjacent another and to which different colors have been imparted.17. The skin-like covering according to claim 10 wherein the lacquerlayer contains a material component contributing to the light stabilitythereof.
 18. The skin-like covering according to claim 10 wherein thethickness of the support or carrier layer amounts to about 0.3 mm toabout 1 mm.
 19. The skin-like covering according to claim 18 wherein thereactive polymer aqueous dispersion of the support or carrier layer isdeposited with the addition of pressurized gas and/or compressed air.20. The skin-like covering according to claim 19 wherein the dropletsize of the gas-supported and/or air supported atomization of thedeposited reactive polymer aqueous dispersion of the support or carrierlayer amounts to about 5μ to 100 μ.
 21. The skin-like covering accordingto claim 20 wherein the support or carrier layer is backed by apolyurethane foam.
 22. A method of making a skin-like covering forautomobile interior parts including arm rests, central consoles, doorcovers and instrument panels for automobiles, in which at least onecolor pigment containing liquid polymer reaction mixture is applied to ashape imparting surface of a tool, said method comprising the steps ofinitially spraying a lacquer layer of a cross linker containing reactivepolymer aqueous single-component or multi-component dispersion in one ormore layers onto a tool having an engraved surface imparting an optionalshape and surface structure which can include a leather graining to thelaquer layer and subsequently spraying a support or carrier layer on abackside of the lacquer layer in one or more layers of a cross linkercontaining reactive polymer aqueous single component or multicomponentdispersion, whereby both the lacquer layer and the carrier layer aresprayed by means of pressurized gas and/or by means of compressed air.23. The method according to claim 22 metering of the material of thedispersion for the lacquer layer and/or the dispersion for the supportor carrier layer is variably adjustable.
 24. The method according toclaim 23 wherein the atomization of the dispersion for the lacquer layer(11) and/or the dispersion for the support or carrier layer (12) isvariably adjustable.
 25. The method according to claim 24 wherein aspray jet shape and/or a spray jet deflection or direction of thedispersion for the lacquer layer and/or the dispersion for the supportor carrier layer iE variably adjustable.
 26. The method according toclaim 25 wherein the material temperature both for the dispersion forthe lacquer layer and the dispersion for the support or carrier layeramounts to about 20° C. to about 120° C.
 27. The method according toclaim 26 wherein both the dispersion for the lacquer layer and thedispersion for the support or carrier layer are applied to an engravedsurface of a workpiece heated to an Operating temperature of about 60°C. to 120° C.
 28. The method according to claim 27 wherein both thedispersion for the lacquer layer and the dispersion for the support orcarrier layer are applied by means of a two-component nozzle spray headwhich preferably are movable in three dimensions.